/**
 * @file
 * MDNS responder private definitions
 */

/*
 * Copyright (c) 2015 Verisure Innovation AB
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without modification,
 * are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice,
 *    this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright notice,
 *    this list of conditions and the following disclaimer in the documentation
 *    and/or other materials provided with the distribution.
 * 3. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
 * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
 * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
 * OF SUCH DAMAGE.
 *
 * This file is part of the lwIP TCP/IP stack.
 *
 * Author: Erik Ekman <erik@kryo.se>
 * Author: Jasper Verschueren <jasper.verschueren@apart-audio.com>
 *
 */
#ifndef LWIP_HDR_MDNS_PRIV_H
#define LWIP_HDR_MDNS_PRIV_H

#include "mdns.h"
#include "mdns_opts.h"

#include <lwip/pbuf.h>

#ifdef __cplusplus
extern "C" {
#endif

#if LWIP_MDNS_RESPONDER

    #define MDNS_READNAME_ERROR 0xFFFF
    #define NUM_DOMAIN_OFFSETS  10

    #define SRV_PRIORITY 0
    #define SRV_WEIGHT   0

    /* mDNS TTL: (RFC6762 section 10)
     *  - 120 seconds if the hostname appears somewhere in the RR
     *  - 75 minutes if not (4500 seconds)
     *  - 10 seconds if responding to a legacy query
     */
    #define MDNS_TTL_10   10
    #define MDNS_TTL_120  120
    #define MDNS_TTL_4500 4500

    /* RFC6762 section 8.1: If fifteen conflicts occur within any ten-second period,
     * then the host MUST wait at least five seconds before each successive
     * additional probe attempt.
     */
    #define MDNS_PROBE_MAX_CONFLICTS_BEFORE_RATE_LIMIT 15
    #define MDNS_PROBE_MAX_CONFLICTS_TIME_WINDOW       10000
    #define MDNS_PROBE_MAX_CONFLICTS_TIMEOUT           5000

    #if LWIP_MDNS_SEARCH
/** Description of a search request */
struct mdns_request {
    /** Name of service, like 'myweb' */
    char name[MDNS_LABEL_MAXLEN + 1];
    /** Type of service, like '_http' or '_services._dns-sd' */
    struct mdns_domain service;
    /** Callback function called for each response */
    search_result_fn_t result_fn;
    void *arg;
    /** Protocol, TCP or UDP */
    u16_t proto;
    /** Query type (PTR, SRV, ...) */
    u8_t qtype;
    /** PTR only request. */
    u16_t only_ptr;
};
    #endif

/** Description of a service */
struct mdns_service {
    /** TXT record to answer with */
    struct mdns_domain txtdata;
    /** Name of service, like 'myweb' */
    // char name[MDNS_LABEL_MAXLEN + 1];
    /** Type of service, like '_http' */
    const char *service;
    // Not used, but left in here to minimize code changes.
    void *txt_userdata;
    /** Protocol, TCP or UDP */
    u16_t proto;
    /** Port of the service */
    u16_t port;
};

/** mDNS output packet */
struct mdns_outpacket {
    /** Packet data */
    struct pbuf *pbuf;
    /** Current write offset in packet */
    u16_t write_offset;
    /** Number of questions written */
    u16_t questions;
    /** Number of normal answers written */
    u16_t answers;
    /** Number of authoritative answers written */
    u16_t authoritative;
    /** Number of additional answers written */
    u16_t additional;
    /** Offsets for written domain names in packet.
     *  Used for compression */
    u16_t domain_offsets[NUM_DOMAIN_OFFSETS];
};

/** mDNS output message */
struct mdns_outmsg {
    /** Identifier. Used in legacy queries */
    u16_t tx_id;
    /** dns flags */
    u8_t flags;
    /** Destination IP/port if sent unicast */
    ip_addr_t dest_addr;
    u16_t dest_port;
    /** If all answers in packet should set cache_flush bit */
    u8_t cache_flush;
    /** If reply should be sent unicast (as requested) */
    u8_t unicast_reply_requested;
    /** If legacy query. (tx_id needed, and write
     *  question again in reply before answer) */
    u8_t legacy_query;
    /** If the query is a probe msg we need to respond immediately. Independent of
     *  the QU or QM flag. */
    u8_t probe_query_recv;
    /* Question bitmask for host information */
    u8_t host_questions;
    /* Questions bitmask per service */
    u8_t serv_questions[MDNS_MAX_SERVICES];
    /* Reply bitmask for host information */
    u8_t host_replies;
    /* Bitmask for which reverse IPv6 hosts to answer */
    u8_t host_reverse_v6_replies;
    /* Reply bitmask per service */
    u8_t serv_replies[MDNS_MAX_SERVICES];
    #ifdef LWIP_MDNS_SEARCH
    /** Search query to send */
    struct mdns_request *query;
    #endif
};

/** Delayed msg info */
struct mdns_delayed_msg {
    /** Signals if a multicast msg needs to be send out */
    u8_t multicast_msg_waiting;
    /** Multicast timeout for all multicast traffic except probe answers */
    u8_t multicast_timeout;
    /** Multicast timeout only for probe answers */
    u8_t multicast_probe_timeout;
    /** Output msg used for delayed multicast responses */
    struct mdns_outmsg delayed_msg_multicast;
    /** Prefer multicast over unicast timeout -> 25% of TTL = we take 30s as
        general delay. */
    u8_t multicast_timeout_25TTL;
    /** Only send out new unicast message if previous was send */
    u8_t unicast_msg_in_use;
    /** Output msg used for delayed unicast responses */
    struct mdns_outmsg delayed_msg_unicast;
};

/* MDNS states */
typedef enum {
    /* MDNS module is off */
    MDNS_STATE_OFF,
    /* Waiting before probing can be started */
    MDNS_STATE_PROBE_WAIT,
    /* Probing the unique records */
    MDNS_STATE_PROBING,
    /* Waiting before announcing the probed unique records */
    MDNS_STATE_ANNOUNCE_WAIT,
    /* Announcing all records */
    MDNS_STATE_ANNOUNCING,
    /* Probing and announcing completed */
    MDNS_STATE_COMPLETE
} mdns_resp_state_enum_t;

/** Description of a host/netif */
struct mdns_host {
    /** Pointer to services */
    const struct mdns_service *services[MDNS_MAX_SERVICES];
    /** Number of probes/announces sent for the current name */
    u8_t sent_num;
    /** State of the mdns responder */
    mdns_resp_state_enum_t state;
    #if LWIP_IPV4
    /** delayed msg struct for IPv4 */
    struct mdns_delayed_msg ipv4;
    #endif
    #if LWIP_IPV6
    /** delayed msg struct for IPv6 */
    struct mdns_delayed_msg ipv6;
    #endif
    /** Timestamp of probe conflict saved in list */
    u32_t conflict_time[MDNS_PROBE_MAX_CONFLICTS_BEFORE_RATE_LIMIT];
    /** Rate limit flag */
    u8_t rate_limit_activated;
    /** List index for timestamps */
    u8_t index;
    /** number of conflicts since startup */
    u8_t num_conflicts;
};

struct mdns_host *netif_mdns_data(struct netif *netif);
struct udp_pcb *get_mdns_pcb(void);

#endif /* LWIP_MDNS_RESPONDER */

#ifdef __cplusplus
}
#endif

#endif /* LWIP_HDR_MDNS_PRIV_H */
